Rollup type doors, characterized generally by a flexible curtain which is wound onto and off of a drum for moving the door between open and closed positions, are used in many applications for covering relatively large openings in various types of buildings. One popular application for the general type of door described herein is for so-called mini-warehouses or personal storage facilities wherein a large number of separate storage enclosures are provided for individual use. Typically, these enclosures utilize a relatively large opening at one end of the enclosure which is closeable by a so-called sheet or rollup type door.
The above mentioned application of rollup type doors, as well as certain other applications for rollup doors, require a lightweight structure of relatively low initial cost and requiring minimal assembly or installation procedures. Accordingly, there is an ever-present requirement to provide rollup type doors which are easily fabricated in large quantities at low cost, are adapted for easy erection or installation but which also are reliable and long-lived in use. In this regard there has been a need to improve the support structure for the door curtain including opposed guide tracks which are provided with wind load resisting or locking features cooperable with the door curtain to resist displacement of the curtain under so-called wind loads or other atmospheric pressure differentials.
There has also been a need to provide improved and simplified support structure for the door curtain including such members as the curtain drum support brackets and the door curtain bottom edge stop members. Still further, there has been a need to provide corrugated door panels with structure which will prevent unreleasable nesting of the corrugations in the door rolled up condition, and provide a configuration of door guide tracks which minimize wear on the tracks and on the curtain during opening and closing of the door and minimal noise generated by engagement of the door curtain with the guide tracks during opening and closing movement and while the door is stationary. The above mentioned desiderata in rollup type door assemblies have been met by the present invention.